Almost incomprehensibly, the humanitarian crisis in Darfur continues to deepen, threatening the millions of people the UN describes as "conflict-affected". Security throughout the humanitarian theatre, including much of eastern Chad, is deteriorating badly. Aid operations now operate among high levels of danger. Hundreds of thousands of civilians may die if there is no significant improvement in security.

More than a million human beings have no access to basic humanitarian aid - food, medical care and clean water. Oxfam International reported in December that more than a third of Darfur's worst-affected population was "effectively out of bounds to aid agencies." This news came as Unicef reported that nutritional studies revealed over 70% of the population is experiencing food insecurity, and localised studies found acute malnutrition affecting 20% of children under five.

There were eight emergency evacuations of humanitarian workers in December alone, involving 400 personnel throughout Darfur. The same number were also evacuated from aid operations in eastern Chad, the scene of rapidly accelerating ethnic violence, most of it by Khartoum's Janjaweed proxies or Chadian rebel groups supported by the National Islamic Front regime.

Humanitarian access is at its lowest ebb since early 2004, the most violent phase of the Darfur genocide. Withdrawals by major humanitarian organizations continue, with a steady erosion of relief capacity. In turn, there are fewer international witnesses to the ethnic crimes that define the conflict in Darfur. Khartoum's crackdown on journalists traveling to the region has also reduced the means of chronicling the accelerating genocide.

This is the context in which to understand President Omar al-Bashir's insistence that Khartoum will not allow UN troops into Darfur - indeed, that Darfur doesn't need UN troops. Asserting that Khartoum's "experience with UN operations in the world is not encouraging," al-Bashir went on to declare: "There are sufficient forces in the Sudan from African countries to maintain order and they can provide order. All we need is funding for the African troops."

It is a political and moral failure of the first order that this mendacity should be the obstacle to deployment of the UN forces needed to protect the collapsing humanitarian operations and vulnerable population. Acquiescence to al-Bashir's defiance makes a mockery of the world's "responsibility to protect" civilians in places such as Darfur. This responsibility was a centerpiece of the September 2005 UN World Summit and was unanimously reaffirmed in UN Security Council Resolution 1674 of April 2006.

Politically savvy, al-Bashir and the National Islamic Front regime realized that their defiance of the UN needed a public relations complement. This was the real significance of the 60-day ceasefire announced during the visit of the US politician and presidential aspirant Bill Richardson, who recently traveled to Sudan - to be followed by Jan Eliasson, UN special representative of the secretary-general. Although packaged as a breakthrough by both Richardson and Khartoum, the reality is that a ceasefire has been nominally in place for more than two years, but has proved meaningless since it began in April 2004.

Moreover, Khartoum's regular forces have been badly mauled recently by rebel groups that did not sign the disastrous Darfur peace agreement in Abuja last year. A ceasefire will allow the regime to regroup its depleted military units in both north and west Darfur. The regime's Janjaweed forces have also suffered significant losses, chiefly at the hands of the potent rebel alliance called the National Redemption Front.

There is no reason to believe that this ceasefire can be monitored any more effectively than the previous one: the African Union (AU) will still do little more than file reports on those few violations it has detected. Khartoum will also continue to hamstring monitoring by denying the AU mission fuel supply for its aircraft, by creating bureaucratic burdens and by imposing flight restrictions.

Moreover, any ceasefire violations that are reported will certainly be justified by Khartoum as "defensive actions," the excuse it repeatedly offers for attacks on civilians. And what will be the consequences for ceasefire violations that are confirmed? What is the AU in a position to do now that it could not do under the terms of the previous ceasefire? What credible penalties are spelled out? There are no encouraging answers.

The non-signatory rebel groups will be watching Khartoum's behavior with a justified skepticism. Violations, whether by the regime's regular forces or militia, will not be accepted passively. The likelihood of the ceasefire holding is exceedingly remote, as are the prospects for meaningful negotiations. Khartoum has ensured that the flawed Darfur peace agreement remains the only basis for further talks. Since the security provisions of the agreement, in particular disarming of the Janjaweed, depend largely upon Khartoum's goodwill, this will be unacceptable both to rebel groups and to those in the refugee camps.

The miserable compensation provisions of the agreement - $30m in the first year, with nothing further guaranteed - would also be preserved if the Abuja agreement is a starting point for renewed negotiations. This represents less than $8 per affected person, compared with the millions of people who have lost everything over the past four years. For Darfuris this is hardly an acceptable basis for negotiations, even as Khartoum successfully insists on enshrining the terms of the agreement - including as a condition of its accepting the new ceasefire.

Khartoum's adamant rejection of the large UN force and robust mandate authorized by Security Council Resolution 1706 remains unchallenged. The consequences will be further deterioration in security for humanitarian operations in Darfur, as well as in eastern Chad. This in turn may trigger increasing evacuations or even total withdrawal by aid groups from Darfur. Civilian mortality will be catastrophic.

This is the grim syllogism of genocidal destruction in Darfur. There is no evidence that the terms have changed or will in the foreseeable future. Until the international community - in particular, China - finds the will to confront Khartoum, a savage genocide by attrition will continue indefinitely.